Open the Google Toolbar options (probably reached via a button on the far right if you don't have it displayed on the toolbar--Gmail is a "custom button") and be sure you have selected the mail icon to appear on the toolbar. If you have new mail the envelope is "open" and there is a down arrow next to that icon. If you mouse over or click ON THAT ARROW it will display your mail in a drop down menu and you can go to whichever one you want to open directly, or simply open the mail page. It won't start doing the open envelope thing until you get new mail in the account.

Hope that helps.

SRS